Please help right this ship

[drknudsenx2]

Tank has been up for about 20 months, and admittedly life has been crazy between a 3 year old, pregnant wife, busy business, and covid, that my tank was being neglected for a number of months. I was probably only water changing once every 2 months or so. All of my fish ( 2 clowns, yellow tang, hippo tang, fire fish) are doing great, as are my hermit crabs, urchin, serpent star, and banded shrimp. I have a magnificent anemone that is volleyball sized and thriving. However, all of my snails are dead, including the newest batch I bought from LFS.
I am also getting some sort of algae over growth or maybe diatom that is being a nuisance.
my corals seem to be thriving, my hammer just grew 4 new heads.
I would greatly appreciate any advice/ help in clearing up this green gunk, or opinions on my snail problem?

75 gallon tank- 20 months old
20 gallon sump
Protein skimmer
Nitrate 0.5
Nitrite 0
pH 8
dKh 6
Ca 460
P 0.15
1.025
78F

I have done 3 water changes in the past 2 weeks and plan to do another one tomorrow.

thank you for any help!

 

[vetteguy53081]

I see red and green cyano. Cyano blooms typically start when water nutrient concentrations go haywire. Just like when you eat too much sugar and your waistline starts to bloom, the same happens in your tank when concentrations of phosphate, nitrate and other organic compounds are too high.
Some of the most common causes include:
- Protein skimmer which fills water with tiny air bubbles. As bubbles form from the reaction chamber, dissolved organic compound molecules stick to them. Foam forms at the surface of the water and is then transferred to a collection cup, where it rests as skimmate. When the protein skimmer does not output the best efficiency or you do not have the suitable protein skimmer to cover the tank, the air bubbles created by the skimmer might be insufficient. And this insufficiency of air bubbles can trigger the cyano to thrive.
- Overstocking / overfeeding, your aquarium with nutrients is often the culprit of a cyano bloom
- Adding live rock that isn’t completely cured which acts like a breeding ground for red slime algae
- If you don’t change your water with enough frequency, you’ll soon have a brightly colored red slime algae bloom. Regular water changes dilute nutrients that feed cyanobacteria and keeps your tank beautifully clear
- Using a water source with nitrates or phosphates is like rolling out the welcome mat for cyano. Tap water is an example
- Inadequate water flow, or movement, is a leading cause of cyano blooms. Slow moving water combined with excess dissolved nutrients is a recipe for pervasive red slime algae development

I recommend to reduce white light intensity or even turn them off for 5-7 days. Add liquid bacteria daily for a week during the day at 1.5ml per 10 gallons. Add Hydrogen peroxide at night at 1ml per 10 gallons. Add a pouch of chemipure Elite which will balance phos and nitrate and keep them in check.

After the week, add a few snails such as cerith, margarita, astrea and nassarius plus 6-8 blue leg hermits to take control.